For which of the following reasons can Hill Climbing get stuck?
This question really looks like a homework problem, in part because it is too vague (what does it mean to 'get stuck' exactly?).

Hill climbing stops when it reaches a local maximum.

Hill climbing is an uninformed search algorithm, so it does not make use of a heuristic.

Hill climbing may or may not stop on a ridge, depending on the implementation. Some common implementations move randomly when equal (but not better) moves are available. Others stop in this situation.

Hill climbing may or may not stop on a plateau, depending on how the implementation handles the case of ties, like with ridges. Whether you think it 'gets stuck' depends a lot on your definition. Implementations that stop when encountering a tie will stop. Implementations that don't stop will eventually exit the plateau through random movements, but it could take infinite time if your movements in the gradient-free region are unlucky.